Casting equipment



Feb. 12, 1952 G. c. KOHL 2,535,662

CASTING EQUIPMENT Filed Dec. 17, 1948 5 Sheets-Sheet 2 i l I! 'l I! m 68 III] I! ll 6 9 70 .96 fo '72 76 lIlllIli 5 I III ull" V Ill 4 IZ; El. m M 4m n g INVENTOR.

GEORGE C. KOHL ATTORNEY.

Feb. 12, 1952 e. c. KOHL 2,585,662

CASTING EQUIPMENT Filed Dec. 17, 1948 5 Sheets-Sheet 5 FIG. 3

INVENTOR.

GEORGE G. KOHL ATTORNEY.

Feb. 12, 1952 e. c. KOHL 5,662

'CASTING EQUIPMENT Filed Dec. 17, 1948 5 Sheets-Sheet 4 FIG. 6

V INVENTOR. GEORGE C. KOHL ATTORNEY.

Feb. 12, 1952 e. c. KOHL 2,535,662

CASTING EQUIPMENT Filed Dec. 17, 1948 s Sheets-Sheet s F'IG. l2

INVENTOR. GEORGE C. KOHL ATTORNEY.

Patented Feb. 12,1952

um EosrAres PATENT OFFICE CASTING EQUIPMENT George 0. Kohl,.University Heights, Ohio, as-

signonto Aluminum Company of America, Pittsburgh,..Pa., a corporation of Pennsylvania Application December 17, 1948, Serial No; 65,770

This invention relates-in general to improvements in casting equipment and is more particularly directed to mechanism for removing or stripping-cast articles from molds in which the articles have been cast.

Casting removing, stripping and/or transferring mechanisms of the type contemplated within the scope of the invention lend themselves to association with casting equipment of the general type described and illustrated in my copending application for United- States Letters Patent, Serial No. 178,520,'filed August 9., 1950, now patent No.'2,581,418issued January 8, 1952.

The configuration, exterior contour and distribution of metal, or other material, in any particular cast articles, are significant factors in respect to the choice of casting equipment and technique to be employed in producing castings. In the case of'cup-shapedarticles, such as pistons for internal combustion engines, there are certain advantages derived from casting the same in the head-up position.- For-example, the metallurgical and physical properties and characteristics of a piston benefit fromthe head-up casting procedure described in United States Letters Patent 2,521,520, issued September 5, 1950, in the name of Charles G..Jancura. Also, the head-up positioning of a cup-shaped casting permits the use of the internal core equipment described in my aforementioned co-pending application.

A machining orfinishing operation is normally performed on castings to remove excess material in the form of gates, sprues, runners and risers. In some cases the removal of this excess material places the casting in condition for subsequent use as a finished cast product. Additional machiningor finishing operations, however, may also be required in cases where an'otherwise cast surface is machined to impart an entirely new configuration thereto. This latter operation may be exemplified by the machined grooves in a cast piston blank for receiving the normally used piston rings.

As an example of a cast article which; combines surfaces that are machined with surfaces that remain in the as cast condition, reference is made herein to an internal combustion engine piston having an as cast exterior head surface that does not readily lend itself to machining' operations to produce a desired contour in the. head of the piston. Typical of the piston referred to is one in which the top exterior surface is cast in the form of an irregular, or nonsymmetrical, undulating contour adapted, in

2 Claims. (01. zz-anf combination with a cylinder head, to control the progress of the flame front during ignitionand burning of the fuel within the combustion chamherof an-internal combustion engine;

Since the. irregularly contoured piston described above does not lend itself to normal machining practices to develop its contoured head, the gating of the mold to produce the same introduces a problem in that riser, gate and sp-rue connections can not be made to the head of the piston, nor can any gating or metal feeding system be employed thatwouldnecessitate a .machining or finishing operation on the contoured headof the piston following its solidification to an as cast surface.

Avoiding. connections of the. gate, sprue" and .or riser with the irregular as cast surface of the piston head described above has resulted in in the. development of a casting mechanism that permits incorporation of a casting stripping device for. removing cast articles from the molds in which they have been cast.

It is a 'generalcobj'ect of the presentinvention to provide improved casting equipment which incorporates positive means for grasping and conveying a cast article to a position removed'from the mold'in which it was cast. 7

It is a, further object of the invention to provide casting equipment for-producing pistons, having irregularly contoured heads, in a head-up position, without includingv a gating system that is'directly, connected to the irregularly contoured head.p,

Another object of the invention is to provide a moltenrmetal'feeding system in associationv with a: casting mechanism that permits introduction of the. molten metalinto a mold cavityrout of contact with an irregular and non-machinable as cast surface.

Other objects and'advantages of the invention will become. apparent on consideration of the following description and drawings in. which:

Fig. 1 representsrafragmentary partial sectional. elevation through'a two-mold piston casting mechanismin which certain elements of the mechanism.- are illustrated. in molten metal re- Fig. 8 represents a sectional plan view to enlarged scale taken alon the plane VIII-VIII of Fig. 1;

Fig. 9 represents a fragmentary sectional elevation to enlarged scale taken along the plane IXIX of Fig. 8;

Fig. 10 represents a sectional plan view to enlarged scale taken along the plane X--X of Fig. 1;

Fig. 11 represents a sectional plan View to en larged scale taken along the plane XI-XI of Fig. 1; and

Fig. 12 represents a sectional plan view to enlarged scale taken along the plane XII-XII of Fig.4. r

The invention and its mode of operation are described hereinafter in terms of equipment suitable for producingintern-al combustion engine pistons. It should be understood that the selection of a piston in no way limits the scope of the invention, since other cast articles may be produced by employing the equipment and practice of the invention.

Referring in general to the casting equipment of the invention, it comprises a pair of medially split molds machined, or otherwise formed, to define cooperatin recesses which provide two casting cavities and inter-related gating systems for producing two pistons in head-up position. The mold sections are operatively mounted on a suitable base member and internal cores for defining the interior surfaces of the pistons are suitably supported beneath the base member.

The mechanism thus far described is similar to that described and illustrated in my co-pending application, Serial No. 178,520, filed August 9, 1950, now Patent No. 2,581,418, issued January 8, 1952. a

Referring to the drawings for a specific description of the invention in its application to a piston casting mechanism, right and left'hand mold sections l 0 and I2, respectively, are slidably mounted through the medium of keys I4 and keepers IE on the top horizontal surface of a main base member or casting l5. Matchingor similar mold sections (Fig. '7 and 11) are provided and supported on the base member [5, it

being understood that each mold includes a pair of similar cooperating sections that are slidable into and out of casting cavity-forming relationship on the base I5.

A casting stripper and conveying device, represented in its entirety by the reference numeral I8, is mounted immediately above the mold members. Device I8 is preferably constructed in the form of a light metal alloy casting and is supported in cantilever relationship upon four vertical posts which extend verticallyupwardly from the main frame I5 of thecasting mechanism. A fiuid-operatedcylinder 22 has itspiston rod 24 secured to the underside of the frame [8 and serves to vertically reciprocate this frame from the position illustrated in Fig. 1 to that shown in Fig. 2. V

Tubular columns 25 are rigidly secured, as b flange and bolt connections, to the underside of frame I8 and depend therefrom in coaxial align with downwardly converging side walls.

ment with each mold cavity therebelow. The tubular columns 25 are also flanged at their lower ends and are rigidly connected by suitable bolts, cap screws, or the like, to ejector pin guide plates 26. The ejector pin guide plates 26 each have a circular block or plug 28 secured to its underside, through suitable bolt connections. Plug members 28 are received within complementary openings in the top surfaces of each pair of mold sections and cooperate therewith to define the casting cavity in each of the molds. The underside of each of the plug members 28 is formed, as by a profiling operation, to define a contoured pistonhead in the actual apparatus herein disclosed.

Fluid-operated cylinders 30 are supported and secured upon the upper surface of frame member l8 with their piston rods 32 depending downwardly through the tubular columns 25. The cylinders 30 may be diaphragm type air cylinders.

Vertically disposed ejector pins 34 and 35 are positioned within guide apertures in the plates 26. The pins 34 and 35 are secured, as by clamp nuts, at their upper ends to an annulus 36 and are surrounded by coiled springs 38, which normally exert an upward pressure against the underside of each annulus 36 to urge the same and the depending ejector pins 34 and 35 upwardly. The springs 38 are preferably encased in tubular shielding members 40, which also serve to limit the downward stroke of pistons 32 through contact with the underside of annuli 36.

Each annulus 36 is provided with aligned bifurcated depending lugs 42 on its underside between which a cross link 44 is secured, as by pin connections. The location of the annuli 36 is such that the cross links 44 pass through slots 45 (Figs. 10 and 11) machined or otherwise formed through the walls of tubular columns 25.

Frame member I8 is provided with a depending column or post member 45 at its outer end removed from the guide columns 20. The column 45 is provided at its lower end with an outwardly projecting hook or terminus 48 formed A complementary cavity 50 is machined or otherwise formed in the base I5 for receiving the terminus 48. If desired, the cavity may be machined or formed in a separate piece of metal or casting and attached to the left hand end of the base member l5, as best illustrated in Fig.6. It will be observed that the complementary inclined surfaces on the terminus 48 and in the cavity 50 (Fig. 5) insure vertical registration of the frame member l8, together with its depending tubular columns 25, ejector pin guide plates 26 and contour blocks 28, with the mold cavities on the base I5. Selection and adjustment of the length of the post member 46 and engagement of the inclined walls of the terminus 48 with the complementary walls of the cavity 55 also insure positive horizontal positioning of the frame [8 and its depending elements in respect to the mold cavities on the base [5. I

A positive mechanical locking mechanism is provided to insure positive assembly of the frame l8 and its depending elements in respect to the molds and base member I5, as well as to lock the frame [8 against unintended vertical remachined. The latch 52 is pin-connected at 55 g to a piston rod 56 which is reciprocally sup;

'7 --btwen the lower blocks .98-and upper plugs 28. The plug members 28: throughv their downwardly tapering: peripheries, frictio'nally engage the incylinders-30 lowers piston rods 32, the lower ends of.which strike. cross links 44 depressing the same together with annuli 35 and ejector pins 34 and;35 against; therupward resilient pressure of springs 38......Theilower ends 401 the ejector pins in their raisedposition .(Figs. 2 and 9) engage solidified, sprue-metal. at. I02 and integral cast projections- E64 extending outwardly from the cylindrical headportions of the pistons. It will be, appreciated that ejector pins 34 may be located within the area of the top of the pistons and engage the pistons. instead of the integral projections 1104; Reciprocation of the ejector pins 34-and 35 will exert a downward pressure on the cast pistons with sufiicientforce toovercome:.-the restraining frictional engagement betweenplug members 28 and riser metal 12, thereby discharging. the pistons. A suitable chute, or thelike; may be 'reciprocated under the depending .pist0ns in the manner described in my copending application, Serial No. 178,520, filed August, 9, 1950. L

. .xThebast pistons. in practice, are machined, or otherwise rough finishedfto remove the excess gate, sprue, runner, and/or riser metal cast integral therewith. It will be observed that no 7 machining isrequiredtover the surfaces defining the; contoured heads of the pistons, all excess metal removing operations being confined to surfaces that ,sumbit to normal machining operations, such aslathe' cutting and-grinding operati0nS. -.'...-.i" r

The mechanism may be manually or power op-v erated.-;..Eor. example, the introduction of fiuid pressureto; cylinders 22, 30. and 58 may be controlled inlproper sequence. and duration in accordancewith the systemdescribed in my aforementioned co-pending application.

What is claimed isz a 1. A' casting .umechanism-comprising a mold provided with a cavity partially defining both'the exterior surface of a finished casting and a riser attached 1 thereto, aplug member reciprocally supported above said mold in alignment with said cav-ity,-said plug member being reciprocable intosaid cavity to -a position therein to further define the exterior surface of the finished castmg and'a wall of the riser; said riser wall defining-surface of the plug member being tapered toward the finished casting and in frictional engagement with said riser on solidification of casting material within the cavity, and ejector member mounted on said plug member and extending through the same into contact with the finished casting, a lost-motion connection between the ejector and plug-members, means for reciprocating the plug member, ejector and frictionally engaged riser and attached finished casting upwardly away from said mold, and means for reciprocating the ejector member relative to said plug member to release frictional engagement of the riser and eject a finished casting and attached'ris'er.

2.,In a casting mechanism comprising a mold provided with a cavity partially defining both a finished casting and a riser integrally connected thereto, a finished casting transfer and stripping device including a plug member reciprocally, mounted in coaxial alignment with the cavity, said plug member extending into said cavity to a position therein to further define an exterior surface of the finished casting and complete the riser, said plug member having a riser wall-defining surface tapered inwardly toward the finished casting in the zone of connection between finished casting and riser, and saidtapered riser wall establishing frictional engagement between the plug member and riser on solidification of casting material within the cavity, an ejector supported on said plug member, said ejector having lost-motion connection with the plug member and establishing resilient engagement with a finished casting, means for reciprocating the plug member, ejector and frictionally engaged riser and finished casting to transfer the same to a new location away from the mold, and means for reciprocating the ejector relative to the plug member to strip the finished casting and connected riser from the plug member.

' GEORGE C. KOHL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 2,375,486 Morin May 8, 1945 

